Continuation of "TOKO Inductors Needed for EM Theremin"

Apparently the post limit on threads is 101...So here, I'll continue the "TOKO Inductors Needed for EM Theremin" thread.



Rick-
I didn't see your second reply from a few days ago- sorry.
Will you simply run the earth ground wire to point 4? As the Hotrodding schematic says, will you attach the ground (middle pin on DIN) to the neutral (left hand pin on DIN)(labeled as pins 2 and 3, respectively on the hotrodding article), or will you run the earth ground directly to point 4? My problem is that I'm not sure where to run my earth ground one I have it wired to the DIN connector. Also, is there another ground in the schematic that isn't earth ground. It has the earth ground symbol on the new and old schematics. What is that all about? I think my teacher will line me up with an electrical engineer so hopefully that'll help me get the power supply and grounding issues figured out.

As far as inductors, I'm using the Bourns inductors listed in the DIY article, the Coilcraft SLOT TEN 5-11 for the 68uH inductor and the TK2417-ND for the 100uH inductor. If you're looking for the Bourns/ JW Miller inductors, they're available at Farnell, and Bourns can send samples of 6302-RC and 6306-RC. My 68uH inductor is a Q min of 30 instead of 60. Do you know what the effects of that could be?

What are you using for antennas? I plan to use the copper pipe described in the DIY article.

Yes, I'm aware of the backorder issues, however my project isn't due until April. I'm getting a decent head start on it :)


JCL-
As far as wire goes, I would like to avoid having to order the huge spools on Digi-key or Mouser. Will the correct gauge copper wire from a hardware store work? What other places can I buy a smaller amount of the proper wire?

Thanks,
Dan

I would recommend wire with teflon insulation.
The teflon insulation will not melt back from soldering iron temperatures.

I wouldn't think you would find it at the
hardware store but maybe you can. Is there an
electronics lab in your school that would give
you some wire? You shouldn't require much for
this project.

(* jcl *)

---
www.luciani.org

I actually found 4 conductor telephone wire 24# at RadioShack, so I'll use that for the power cable and for some hookups.

I got a PVC box for the power supply that is insulated and easy to fasten shut.


Thanks,
Dan

By "power cord" I am assuming you mean the
+-12V (or 15V) DC. Do not telephone wire for
the 120VAC.

(* jcl *)

That's correct. It's for the power supply box to the Theremin :)

The plans note that I section of shielded wire is needed for a connection from the main circuit to the panel. What connection is this for? I bought some shielded audio cable at RadioShack- will it work?

Thanks

Once I've finished the board, what is the best way to attach it to the inside of the theremin box, and the power supply board to the inside of the PVC power supply box?

I would use aluminum or plastic standoffs
placed at the four corners of each board.
Get threaded standoffs with a 4-40 thread.
If the transformer is heavy you could place
additional standoffs near it to prevent the
board from sagging.

I usually get these from McMaster Carr but
since you only need a few just add them to
a Digikey or Mouser order. Radio Shack should
have them as well.

(* jcl *)

Thanks,

On last clarification for the power supply (Here's the link to it: techSpecs=techSpecs¤tTab=accessories&
cp=&
custRatings=custRatings&
features=features&
accessories=accessories&
productId=2103732&
support=support&
tab=summary>... the transformer has two black primaries, two yellow secondaries, and one black secondary. How do I know what primary to connect the hot wire from the wall to, and which one to connect the wall neutral to? With the secondary, I only need 1 line and 1 neutral (I believe). Which yellow of the secondary will be my line. Is the secondary, I assume the black is the neutral (?). This will go into the circuit as shown in the schematic. Since I will only use one of the secondary's yellows (I assume that one is the main line and the other the center-tap, how will I know which one to use, and what should I do with the remaining yellow?

Thanks,
Dan

P.S. Do you know what that shielded wire is for in the connections between the circuit and the panel?

Also, all the power supply appears to have is holes for screw mounting. In this case, how should I attach the transformer to the board?

Thanks!